129 research outputs found
The effect of glycemic control on renal triglyceride content assessed by proton spectroscopy in patients with type 2 diabetes mellitus: a single-center parallel-group trial
Objective: Ectopic lipid accumulation in the kidney (fatty kidney) is a potential driver of diabetic kidney disease, and tight glycemic control can reduce risk of diabetic nephropathy. We assessed whether glycemic control influences renal triglyceride content (RTGC). Furthermore, we compared glucagon-like peptide-1 receptor agonist liraglutide versus standard glucose-lowering therapy. Design andMethods: In this single-center parallel-group trial, patients with type 2 diabetes mellitus were randomized to liraglutide or placebo added to standard care (metformin/sulfonylurea derivative/insulin). Changes in RTGC after 26 weeks of glycemic control measured by proton spectroscopy and difference in RTGC between treatment groups were analyzed.Results: Fifty patients with type 2 diabetes mellitus were included in the baseline analysis (mean age, 56.5 +/- 9.1 years; range, 33-73 years; 46% males). Seventeen patients had baseline and follow-up measurements. Mean glycated hemoglobin was 7.8 +/- 0.8%, which changed to 7.3 +/- 0.9% after 26 weeks of glycemic control irrespective of treatment group (P = .046). Log-transformed RTGC was -0.68 +/- 0.30% and changed to -0.83 +/- 0.32% after 26 weeks of glycemic control irrespective of treatment group (P = .049). A 26-week-to-baseline RTGC ratio (95% confidence interval) was significantly different between liraglutide (-0.30 [-0.50, -0.09]) and placebo added to standard care (-0.003 [-0.34, 0.34]) (P = .04).Conclusion: In this exploratory study, we found that 26 weeks of glycemic control resulted in lower RTGC, in particular for liraglutide; however, larger clinical studies are needed to assess whether these changes reflect a true effect of glycemic control on fatty kidney. (C) 2020 The Authors. Published by Elsevier Inc. on behalf of the National Kidney Foundation, Inc.Cardiovascular Aspects of Radiolog
Renal sinus fat volume in type 2 diabetes mellitus is associated with glycated hemoglobin and metabolic risk factors
Aims We aimed to compare renal sinus fat volume assessed by MRI between patients with type 2 diabetes and healthy volunteers, and investigate the association between renal sinus fat and metabolic traits.Methods In this cross-sectional study, renal sinus fat and parenchyma volumes measured on abdominal MRI were compared between patients and controls using analysis of covariance. Associations of renal parameters with clinical characteristics were analyzed using linear regression analysis.Results A total of 146 participants were enrolled, consisting of 95 type 2 diabetes patients (57.2 +/- 8.8 years, 49.5% male) and 51 controls (54.0 +/- 9.2 years, 43.1% male). Patients with diabetes demonstrated larger sinus fat volumes (15.4 +/- 7.5 cm(3) vs. 10.3 +/- 7.1 cm(3), p < 0.001) and sinus fat-parenchyma ratio than controls. In the total population, renal sinus fat was positively associated with HbA1c, abdominal VAT, cholesterol and triglycerides, after adjustment for age, sex, ethnicity and type 2 diabetes. In type 2 diabetes patients, increased sinus fat volume was significantly associated with urinary albumin-to-creatinine ratio.Conclusion Renal sinus fat volume is positively associated with several metabolic risk factors including HbA1c level and urinary albumin-to-creatinine ratio in type 2 diabetes patients, indicating a potential role of renal sinus fat in the development of diabetic nephropathy. Future studies are needed to investigate whether sinus fat volume can serve as an early biomarker for diabetic nephropathy.Diabetes mellitus: pathophysiological changes and therap
Constant Curvature Coefficients and Exact Solutions in Fractional Gravity and Geometric Mechanics
We study fractional configurations in gravity theories and Lagrange
mechanics. The approach is based on Caputo fractional derivative which gives
zero for actions on constants. We elaborate fractional geometric models of
physical interactions and we formulate a method of nonholonomic deformations to
other types of fractional derivatives. The main result of this paper consists
in a proof that for corresponding classes of nonholonomic distributions a large
class of physical theories are modelled as nonholonomic manifolds with constant
matrix curvature. This allows us to encode the fractional dynamics of
interactions and constraints into the geometry of curve flows and solitonic
hierarchies.Comment: latex2e, 11pt, 27 pages, the variant accepted to CEJP; added and
up-dated reference
Vaccine-induced, but not natural immunity, against the Streptococcal inhibitor of complement protects against invasive disease
Highly pathogenic emm1 Streptococcus pyogenes strains secrete the multidomain Streptococcal inhibitor of complement (SIC) that binds and inactivates components of the innate immune response. We aimed to determine if naturally occurring or vaccine-induced antibodies to SIC are protective against invasive S. pyogenes infection. Immunisation with full-length SIC protected mice against systemic bacterial dissemination following intranasal or intramuscular infection with emm1 S. pyogenes. Vaccine-induced rabbit anti-SIC antibodies, but not naturally occurring human anti-SIC antibodies, enhanced bacterial clearance in an ex vivo whole-blood assay. SIC vaccination of both mice and rabbits resulted in antibody recognition of all domains of SIC, whereas naturally occurring human anti-SIC antibodies recognised the proline-rich region of SIC only. We, therefore, propose a model whereby natural infection with S. pyogenes generates non-protective antibodies against the proline-rich region of SIC, while vaccination with full-length SIC permits the development of protective antibodies against all SIC domains
Altered high-density lipoprotein composition is associated with risk for complications in type 2 diabetes mellitus in South Asian descendants: a cross-sectional, case-control study on lipoprotein subclass profiling
Background: Composition of high-density lipoproteins (HDL) is emerging as an important determinant in the development of microvascular complications in type 2 diabetes mellitus (T2DM). Dutch South Asian (DSA) individuals with T2DM display an increased risk of microvascular complications compared with Dutch white Caucasian (DwC) individuals with T2DM. In this study, we aimed to investigate whether changes in HDL composition associate with increased microvascular risk in this ethnic group and lead to new lipoprotein biomarkers. Materials and Methods: Using H-1 nuclear magnetic resonance spectroscopy and Bruker IVDr Lipoprotein Subclass Analysis (B.I.LISA) software, plasma lipoprotein changes were determined in 51 healthy individuals (30 DwC, 21 DSA) and 92 individuals with T2DM (45 DwC, 47 DSA) in a cross-sectional, case-control study. Differential HDL subfractions were investigated using multinomial logistic regression analyses, adjusting for possible confounders including BMI and diabetes duration. Results: We identified HDL compositional differences between healthy and diabetic individuals in both ethnic groups. Specifically, levels of apolipoprotein A2 and HDL-4 subfractions were lower in DSA compared with DwC with T2DM. Apolipoprotein A2 and HDL-4 subfractions also negatively correlated with waist circumference, waistto-hip ratio, haemoglobin A1c, glucose levels and disease duration in DSA with T2DM, and associated with increased incidence of microvascular complications .Conclusion: While HDL composition differed between controls and T2DM in both ethnic groups, the lower levels of lipid content in the smallest HDL subclass (HDL-4) in DSA with T2DM appeared to be more clinically relevant, with higher odds of having diabetes-related pan-microvascular complications such as retinopathy and neuropathy. These typical differences in HDL could be used as ethnicity-specific T2DM biomarkers.Metabolic health: pathophysiological trajectories and therap
Partial symmetry breaking and heteroclinic tangencies
We study some global aspects of the bifurcation of an equivariant family of
volume-contracting vector fields on the three-dimensional sphere. When part of
the symmetry is broken, the vector fields exhibit Bykov cycles. Close to the
symmetry, we investigate the mechanism of the emergence of heteroclinic
tangencies coexisting with transverse connections. We find persistent suspended
horseshoes accompanied by attracting periodic trajectories with long periods
Caloric restriction lowers endocannabinoid tonus and improves cardiac function in type 2 diabetes
Background/ObjectivesEndocannabinoids (ECs) are associated with obesity and ectopic fat accumulation, both of which play a role in the development of cardiovascular disease (CVD) in type 2 diabetes (T2D). The effect of prolonged caloric restriction on ECs in relation to fat distribution and cardiac function is still unknown. Therefore, our aim was to investigate this relationship in obese T2D patients with coronary artery disease (CAD).Subjects/MethodsIn a prospective intervention study, obese T2D patients with CAD (n = 27) followed a 16 week very low calorie diet (VLCD; 450–1000 kcal/day). Cardiac function and fat accumulation were assessed with MRI and spectroscopy. Plasma levels of lipid species, including ECs, were measured using liquid chromatography-mass spectrometry.ResultsVLCD decreased plasma levels of virtually all measured lipid species of the class of N-acylethanolamines including the EC anandamide (AEA; −15%, p = 0.016), without decreasing monoacylglycerols including the EC 2-arachidonoylglycerol (2-AG). Baseline plasma AEA levels strongly correlated with the volume of subcutaneous white adipose tissue (SAT; R2 = 0.44, p p p p p p p p = 0.016).ConclusionsCaloric restriction in T2D patients with CAD decreases AEA levels, but not 2-AG levels, which is paralleled by decreased lipid accumulation in adipose tissue, liver and heart, and improved cardiovascular function. Interestingly, baseline AEA levels strongly correlated with SAT volume. We anticipate that dietary interventions are worthwhile strategies in advanced T2D, and that reduction in AEA may contribute to the improved cardiometabolic phenotype induced by weight loss.Molecular Physiolog
New Strong-Field QED Effects at ELI: Nonperturbative Vacuum Pair Production
Since the work of Sauter, and Heisenberg, Euler and K\"ockel, it has been
understood that vacuum polarization effects in quantum electrodynamics (QED)
predict remarkable new phenomena such as light-light scattering and pair
production from vacuum. However, these fundamental effects are difficult to
probe experimentally because they are very weak, and they are difficult to
analyze theoretically because they are highly nonlinear and/or nonperturbative.
The Extreme Light Infrastructure (ELI) project offers the possibility of a new
window into this largely unexplored world. I review these ideas, along with
some new results, explaining why quantum field theorists are so interested in
this rapidly developing field of laser science. I concentrate on the
theoretical tools that have been developed to analyze nonperturbative vacuum
pair production.Comment: 20 pages, 9 figures; Key Lecture at the ELI Workshop and School on
"Fundamental Physics with Ultra-High Fields", 29 Sept - 2 Oct. 2008,
Frauenworth Monastery, Germany; v2: refs updated, English translations of
reviews of Nikishov and Ritu
Relativistic Laser-Matter Interaction and Relativistic Laboratory Astrophysics
The paper is devoted to the prospects of using the laser radiation
interaction with plasmas in the laboratory relativistic astrophysics context.
We discuss the dimensionless parameters characterizing the processes in the
laser and astrophysical plasmas and emphasize a similarity between the laser
and astrophysical plasmas in the ultrarelativistic energy limit. In particular,
we address basic mechanisms of the charged particle acceleration, the
collisionless shock wave and magnetic reconnection and vortex dynamics
properties relevant to the problem of ultrarelativistic particle acceleration.Comment: 58 pages, 19 figure
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